1. Field of the Invention
This invention relates generally to phased array antennas and more particularly to the architecture of a phased array antenna comprised of one or more antenna tiles consisting of a plurality of laminated circuit boards including various configurations of printed circuit wiring and components.
2. Description of Related Art
Phased array antennas for radar applications are generally known. More recently, the architecture of a radar antenna, particularly for space based radar applications, has resulted in the design of basic building blocks in the form of xe2x80x9ctilesxe2x80x9d wherein each tile is formed of a multi-layer printed circuit board structure including antenna elements and its associated RF circuitry encompassed in a laminated assembly, and wherein each antenna tile can operate by itself, as a phased array or as a sub-array of a much larger array antenna.
Each tile is a highly integrated module that serves as the radiator, the transmit/receive (TR) module, RF and power manifolds and the control circuitry therefor, all of which are combined into a low cost light-weight assembly for implementing an active aperture, electronically, scanned, array (AESA). Such an architecture is particularly adapted for airborne or space applications.
Accordingly, it is an object of the present invention to provide an improvement in phased array antenna systems. It is a further object of the invention to provide an improvement in antenna tile architecture.
It is still a further object of the invention to provide an improved architecture of an antenna tile which is particularly adapted for space based radar applications.
The foregoing and other objects are achieved by a phased array antenna tile which is steered by microelectromechanical system (MEMS) switched time delay units (TDUs) in an array architecture which reduces the number of amplifiers and circulators needed for implementing an active aperture electronically scanned array antenna so as to minimize DC power consumption, cost and mass of the system which makes it particularly adaptable for airborne and spaceborne radar applications.
In one aspect of the invention, it is directed to a phased array antenna of an active aperture electronically scanned antenna system, comprising: one or more antenna tile structures, each tile of which further comprises a laminated assembly including a plurality of contiguous layers of dielectric material having patterns of metallization formed on one or more surfaces thereof and selectively interconnected by an arrangement of surface conductors and conductive vias for implementing transmission, reception, and control of RF signals between an RF input/output terminal and of an antenna assembly including a plurality of radiator elements wherein said radiator elements comprise elements of a space-fed patch antenna assembly including first and second mutually adjacent arrays of aligned patch radiators located on respective layers of foam material on one side of the antenna tile structure; and, a plurality of MEMS type switched time delay units (TDUS) mounted on the other side of the antenna tile structure, being packaged in groups of four in a Quad TDU package and being coupled between the antenna elements and a signal circulator comprising one circuit element of a transmit/receive (TR) circuit including a transmit signal amplifier and a receive signal low noise amplifier, each of said MEMS type switched time delay units respectively including a set of four identical delay transmission line assemblies having a plurality of different length time delay segments selectively interconnected by a plurality of microelectromechanical switch (MEMS) devices for steering one radiator element.
Further scope of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood, however, that the detailed description and specific example, while disclosing the preferred embodiment of the invention, it is provided by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.